Forced air induction systems are used in vehicles as a way to increase the efficiency of an engine and reduce the emissions of the vehicle. A turbocharger is one example of such a forced air induction system. A turbocharger can include, for example, a turbine and a compressor. In use, exhaust gas that passes through a turbine can provide power and energy for a compressor to compress air and direct the compressed air to the intake manifold of the engine.
In certain situations, it can be useful to employ a closed engine breather systems in a gas or diesel engine. A closed breather system can recirculate gases escaping from the combustion chambers and passing into the crankcase back into the air intake system. These recirculated gases can then be recirculated back to the intake manifold to be burned upon the next pass into the engine. Such closed engine breather systems can help lower the engine emissions because they allow engine blow-by gases to be passed through the engine after-treatment system. Additionally, closed breather systems can reduce the amount of crankcase gasses that are able to enter into the passenger compartment of the vehicle.
A closed breather system traditionally includes a breather tube connected to an air inlet system that is downstream from the air filter and upstream of the engine, compressor, or supercharger air inlet. On a turbocharged engine, for example, this breather tube is often located just before (i.e., upstream of) the turbocharger compressor inlet. However, the recirculated air is often relatively humid and thereby carries with it a significant amount of moisture. This moisture can accumulate along the air intake manifold, or air inlet duct, particularly at the location of the breather port. In cold weather, this accumulation of moisture can freeze, resulting in ice buildup in the closed engine breather system. This ice can break off and fall into a spinning turbocharger compressor wheel, which can cause significant damage. Reducing the accumulation of ice in a closed engine breather system can reduce damage on a turbocharger compressor wheel.